Dream Demon in Amity
by SA-ramblings
Summary: An exchange student found his way into Amity Park, and Danny and his friends question his sanity. There's something weird with him, but he isn't the sociable type. On top of that, Danny's having trouble with his ghost powers again- the first time in years! With only the 3-day weekend to fix it, what's wrong? Whatever, hide it from William! Rev!Bill AU. CWs inside, cover pending.
1. Chapter 1

((A/N: Howdy, how's it goin'? Thank you for taking time out of your mortal life to read these silly symbols on an otherwise-blank screen! This is a Danny Phantom crossover with... not quite Gravity Falls, but with an AU derived from GF's very own demon, Bill Cipher! :D And like that yellow triangle, I've got some plans! Feel free to mention anything you want in a review or PM! Art is nice, too!

I've had this idea for a while now, and I've wanted to do something about it. This was supposed to be a continuation from Dimensional Twins, but unfortunately I scrapped that and left it on forever hiatus. I expect this won't be a very long fic either, but let's see.

Aaaaanyway, this may have body horror, violence, swearing, and dirty jokes and shipping implications, but nothing outright. Nothing too NSFW, since I'm all for asexuality,,, I don't know where in DP this fic fits exactly, but I know that Phantom Planet never happens here.

Have at it! :D))

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A new kid showed up at school today. An exchange student, to be exact, and Danny knew that it wasn't going to be the same for a while.

He wasn't actually that sociable for a guy with blue hair covering half of his face. Granted, he wore a white button-down shirt, dress shoes, and a tie on the regular, but the blue hair had to mean something. Only the cool people at Casper High had ever dyed their hair. Paulina had golden streaks in hers one week and that was the best week of Danny's life.

That being said, the exchange student hasn't really met anyone yet because he always has his nose in that giant book of his. Maybe that was a good thing, since it would mean less trouble for him to cause, but Danny couldn't help but feel bad for the kid. He remedied that by letting the student sit next to him in Mr. Lancer's class, but still, it didn't compensate enough.

That's why he, Sam, and Tucker agreed to asking if he wanted to hang out after school.

William Rephic, though- that was a weird name.

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The trio of kids gathered at their usual lunch table outside, discussing their plans for the well-awaited weekend.

"Are you sure he'll even say yes? After all, he only knows you from Lancer's class, and he's only been here for about a week," Sam asked through her ultra-recyclo-vegetarian lunch. Tucker gagged.

"Never know 'till we try, right?" Danny replied. "I'll just ask him after class. What's the worst that could happen?"

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"I really appreciate the invitation, b-but I'm going to have to decline. I have a lot of studying to do, you know?" William said regretfully, with a hint of an English accent he couldn't quite place. Danny could see the student trying to avoid his stare as he started to pack up his books in a brown messenger bag.

"Who needs to study when you're one of the best students in the school already?" Danny asked, genuinely curious. "You end up doing that at any other moment of the day, don't you want to be a normal kid every once in a while?"

For whatever reason, William winced a little at the mention of being "normal." Was he not?

Well, actually, wearing formal clothing and having dyed hair made for a very not-normal person, but he himself was half-ghost and didn't really have a right to say anything about being normal. Maybe they could talk it out.

"Hey, well, I'll give you my address anyway. My friends and I are actually offering our friendship to you- that gesture shouldn't be taken lightly," Danny explained. He was trying, okay? William was cool enough to be offered at least that much, and Danny scribbled "Fenton Works" along with his address onto a slip of paper.

"Y-yeah... I suppose..." a quiet voice muttered in response.

"We're going to hang out tomorrow, sometime in the afternoon. Feel free to... uh... bring your stuff if you want," Danny offered, handing the kid the address, before walking away.

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It was surprising, but William actually showed up at the front door of Fenton Works. Maddie Fenton got to the door first, and -excitedly as moms do- told him that her son was up in his room with his friends. He decided to hurry his pace when she went to look for the family albums, definitely not in the mood to see a mother embarrass her children for hours on end.

To him, it seemed like a regular visit to someone else's home, but it would soon change into something more... interesting. The shy demeanor definitely did wonders for peer opinions.

Everyone's eyes looked to the teen in the doorway of Danny's room, the latter nervously slinking back behind the door upon realizing he was noticed.

It took a bag of off-brand candy to coax William to join Danny, Sam, and Tucker in Danny's room, but it was worth it when they learned who he was. Apparently he wasn't technically an exchange student of his own will, but he was recently orphaned in an accident from his home country and taken in by his current legal guardian. The rent was too high in California, so the pair had to move to a cheaper apartment- and coincidentally, Amity Park. It was a shock to everyone, and they all mentally gave thanks for having parents that cared for them.

"Seems like you coped pretty fast, though, since you just straight-up told us... that..." Sam trailed off, not that willing to finish her sentence.

William sighed.

"...W-With everything that's been going on, it's been hard to take time to grieve. I miss them, sure, b-but I didn't have that many friends to leave behind anyway, so, that means... you're some of the first acquaintances I've ever made..." He looked down at his dress shoes in a sort of shame.

Tucker reacted first, standing up from his seat on Danny's bed to put a hand on William's shoulder. "Don't worry, Will! We can call you that, right? You can call us friends of yours! You seem like a nice guy, so we might as well explain ourselves too. You shouldn't be the only one that spills their life story! Danny, you first."

Said teen jumped at hearing his name. "Y-yeah, well... I'm from a family that is really into supernatural-"

"Just say 'ghosts', Danny. It's easier on all of us," Sam interrupted, sighing. Danny glared at her for a moment, but continued.

"...Really into ghosts, and I haven't been a fan of it so I wanted to be an astronaut..."

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After saying introductions and settling down again, Tucker began messing with his PDA, Sam and Will went on to talk about their interests and various school subjects, while Danny lounged on the bed, listening to the conversation and white noise from downstairs.

Suddenly his breath went cold, a wisp of air came out in a gasp, and he was up on his feet, startling his guests.

"Aw man, who's out there THIS time?" Tucker whined, wandering to the window in annoyance.

No one answered him, with Sam was busy tossing various metal inventions into her backpack, and Danny was mysteriously nowhere in sight.

Will was told to stay in Danny's room, in accordance to Tucker's request, but Will wasn't the obedient type when he was curious and stepped down the stairs to where the rest of his friends were.

...

A flash of green and a loud crash greeted him at the door as he just barely missed getting hit with the ectoplasmic body of a creature. It was hard to tell what exactly it was, but it had the body of a cat, three viper heads, and a wispy tail that almost hit Will on the way down, billowing up clouds of dust and rubble as Will desperately flailed about to keep his hair covering his face. A thin shot of green blindly peeled away from the dust, a last attempt at revenge, nicking a vaguely-familiar figure in the shoulder.

The figure rubbed away the pain with a wince before diving at the monster with a devastating kick to its body. Dazed and recoiling from pain, it did little to escape from the suction of a... thermos?

...

After the monster was sealed away, the familiar figure flew off and out of sight. Sam turned back to the house to deliver the rampaging ghost back to the Ghost Zone, only to bump into Will at the front door.

"W-Will?! We told you to stay inside!" She said, worried at how much he saw.

"So so sorry! I just... I wanted to know where you guys went... A-And... Is Danny okay? He disappeared without a trace once that things showed up!" Will was clearly concerned, and even though she knew he was fine, she felt the need to say something.

"He just went to get some help. Though, that fight was over so fast I don't think it was necessary," she said carefully. She needed to think of something; Danny was probably up in his room cleaning his wounds, and she need to kill some time so he could cover up. "If you want, you can come with me to see his parents' lab. It's got some pretty cool stuff in there you might like."

Will was confused with the sudden change of subject, but he agreed to a little peek anyway.

It might be useful.


	2. Chapter 2

"So this is the lab I was telling you about," Sam said with a touch of amusement. She wouldn't admit it out loud, but knowing a friend with such... interesting... parents was pretty cool. She couldn't help but feel a bit proud when Will gaped a bit at all the scraps of metal and weird contraptions.

"T-This is really cool! All these strange inventions... B-But isn't it a little dangerous to be leaving all these things out in the open? They're all practically begging to be stolen..." Will worried, clearly more concerned than excited now. Was he always like this? He seemed so quiet around people. Maybe that book of his he always carries around is evidence of that...

"Don't worry about that! It's actually pretty hard to get past the security system that's all over the house- the only reason why I have access to this lab at all is because I..." She paused. "I-I know Danny, I know his sister, and I know his parents. And they trust me."

"...Trust..."

"Huh?"

"N-Nothing... It was nothing," Will muttered, shaking his head. He quickly began asking about what certain inventions did, more interested in how they would affect ghosts than about his trust issues.

Trust no one, that was a universal rule.

Now that he basically had all these inventions at his fingertips, he made a mental note to access these later, should the need arise. After all, the simple plan he was conspiring didn't require weapons.

At least he hoped it wouldn't. He wasn't a fan of violence.

As Will was told to meet Sam back up the stairs, he didn't see the flash of green as the Ghost Portal open up and consume the ghost monster from a metallic thermos.

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Sam and Will's trip down to the lab allowed just enough time for Danny to ice up his bruises and slip on a clean shirt- his other one got torn up before he could go ghost. Though he felt a peculiar buzz of pain in his shoulder that still made him hiss in pain, he didn't have the time to worry about it nor the right gauze to wrap it up -he was going to get some more supplies yesterday, but Past-Danny insisted that that was Future-Danny's responsibility. He's still kicking himself for thinking that was a good idea.

Tucker was out buying more gauze, but he only agreed to it after screaming at Danny for twenty-million years. A wrapped towel was the best he could manage until then.

Despite the sting that came with fibers rubbing on raw flesh that just didn't want to heal, Danny managed a weary smile as the two teens returned to his room. Will sat in Danny's desk chair, somewhat avoiding his eyes and staring at the little things on the desk; it was strange until Sam walked up to his seat on the bed, sat down, and asked how the ghost boy was doing.

"I asked Will to stay off a bit while I asked you about this; I made him think you're hurt because of collateral damage from that ghost- go tell him you're okay before he goes paranoid," Sam explained, elbowing her friend in the side. Danny laughed.

"Yeah, I am- hey, Will!" The teen perked up at the sound of his name. "I'm fine; you don't need to worry about me, okay?"

"O-Oh, that's good! The way Sam talked about you, it sounded like you almost died!" Will said, kneading his hands. "I... I don't need anyone I know to die on me, you know."

Suddenly the room felt cold, and Danny put a comforting hand on his shoulder, making Will flinch and look up at Danny with a look the ghost teen hadn't ever seen in a kid his age. It was like he knew more things than he liked to let on.

Was this person really just a kid? He put that thought aside.

"Don't worry, Will! If I ever need to die, I'll let you know in advance," Danny brightened up, raising a bout of laughter from his friends in the room.

...

Loud footsteps rang through the house as Tucker burst into Danny's room with a plastic bag.

"DANNY, ARE YOu okayyyy..." Tucker trailed off, seeing the three other people in the room. "Uhh... Do I need to explain anything?"

"Nah, we got it covered. Did you get any food?" Sam asked, half-joking.

"Ha-ha, very funny. But yeah, I got some stuff with the extra cash I got from my dad," Tucker answered, to her pleasant surprise. Everyone dug into the snacks as they were being pulled out, as Tucker secretly handed a roll of gauze to a rather grateful Danny.

"You owe me, dude."

"I know..."

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No one realized, but the sun was well-below the horizon before Sam, Tucker, and Will were sent home. The two closer friends offered to escort Will home, but he gracefully declined- they didn't need to see where he lived.

But the reason why they offered to escort him was because of the sheer number of ghosts that haunted Amity Park at night; he never really noticed them before because he always went straight back to the apartment after school, but it was easy to see Amity Park's ghost infestation now. He didn't really have a problem scaring off things weaker than him, but his method of intimidation didn't work on the weak-minded.

Speaking of which...

"I AM THE BOX GHOST! FEAR MEEEE!" the warehouse ghost howled. Will sighed: him again.

"Please move along before I rip your ectoplasmic jugular out of your body. Trust me when I say it isn't beneath me," he threatened, exasperated and clearly unamused. He felt a flash of heat from his hands as they glowed blue in the corner of his working eye.

The message took a moment to process, but then the Box Ghost quickly disappeared in a puff of ectoplasmic energy with genuine fear in his eyes.

Satisfied, Will continued on his way, ghost-free.

...

Despite his refusal for an escort, Sam trailed behind Will anyway. A vulnerable, nervous kid like him shouldn't be wandering around Amity's streets alone, right? That was a recipe for disaster.

But after what she just saw, she wasn't so sure the new kid should stick around their friend group anymore.

For the first time in a long while, she was afraid.

Was...

Was that really Will?


End file.
